\documentclass{standalone}
\usepackage{tikz}
\usepackage{ctex,siunitx}
\setCJKmainfont{Noto Serif CJK SC}
\usepackage{tkz-euclide}
\usepackage{amsmath}
\usepackage{wasysym}
\usepackage{circuitikz}
\usetikzlibrary{patterns, calc}
\usetikzlibrary {decorations.pathmorphing, decorations.pathreplacing, decorations.shapes}
\ctikzset{bipoles/length=1cm}
\begin{document}
\small
\begin{circuitikz}[>=latex, scale=1.0]
  % \useasboundingbox(0.9,0)rectangle(5.1,5);
  \fill[inner color=white,outer color=lightgray,even odd rule](0,0)circle(1.3)(0,0)circle(0.8);
  \foreach \x in {-100,-80,...,200}
  {
    \draw(\x:1.30)--(\x:0.8)arc(\x+90:\x+270:0.01);
    \draw(\x:1.30)arc(\x-90:\x+90:0.01);
  }
  \draw(-3,0)--(-1.7,0)--(-1.7,0|-220:1.3)--(220:1.30)node[below left]{$A$}--(220:0.8)arc(310:490:0.01);
  \draw(240:1.3)node[below]{$B$}--(240:1.7)--(-0.85,-2)--(-3,-2);
  \draw(-0.85,-2)--(2,-2)(0,0)--(0,-0.2)--(2,-0.2);
  \draw[->](0,0)--(40:0.7)node[below]{$P$};
  \draw[fill=white](-3,-2)circle(0.05)(-3,0)circle(0.05)(2,-2)circle(0.05)(2,-0.2)circle(0.05)(0,0)circle(0.05);
  \fill(-0.85,-2)circle(0.05);
  \draw[<->](-3,-1.95)--(-3,-0.05)node[midway,left]{$U_1$};
  \draw[<->](2,-1.95)--(2,-0.25)node[midway,right]{$U_2$};
\end{circuitikz}
\end{document}